When constructing a home or a facility, it is well known to provide garage doors which utilize a motor to provide opening and closing movements of the door. Motors may also be coupled with other types of movable barriers such as gates, windows, retractable overhangs and the like. An operator is employed to control the motor and related functions with respect to the door. The operator receives command input signals—for the purpose of opening and closing the door—from a wireless portable remote transmitter, from a wired or wireless wall station, from a keyless entry device or other similar device. It is also known to provide safety devices that are connected to the operator for the purpose of detecting an obstruction so that the operator may then take corrective action with the motor to avoid entrapment of the obstruction.
To assist in moving the garage door or movable barrier between limit positions, it is well known to use a remote radio frequency (RF) or infrared transmitter to actuate the motor and move the door in the desired direction. These remote devices allow for users to open and close garage doors without having to get out of their car. These remote devices may also be provided with additional features such as the ability to control multiple doors, lights associated with the doors, and other security features. As is well documented in the art, the remote devices and operators may be provided with encrypted codes that change after every operation cycle so as to make it virtually impossible to “steal” a code and use it at a later time for illegal purposes. An operation cycle may include opening and closing of the barrier, turning on and off a light that is connected to the operator and so on.
Although remote transmitters and like devices are convenient and work well, the remote transmitters sometimes become lost, misplaced or broken. In particular, the switch mechanism of the remote device typically becomes worn after a period of time and requires replacement. And although it is much easier to actuate the remote transmitter than for one to get out of an automobile and manually open the door or access barrier, it is believed that the transmitter and related systems can be further improved to obtain “hands-free” operation. Although there are some systems that utilize transponders for such a purpose, these systems still require the user to place an access card or similar device in close proximity to a reader. As with remote transmitters, the access cards sometimes become lost and/or misplaced. A further drawback of these access cards is that they do not allow for programmable functions to be utilized for different operator systems and as such do not provide an adequate level of convenience.
Another type of hands-free system utilizes a transponder, carried by an automobile, that communicates with the operator. The operator periodically sends out signals to the transponder carried in the automobile and when no return signal is received, the operator commands the door to close. Unfortunately, the door closing may be initiated with the user out of visual range of the door. This may lead to a safety problem inasmuch as the user believes that the door has closed, but where an obstruction may have caused the door to open and remain open thus allowing unauthorized access.
U.S. patent application Ser. No. 10/744,180, assigned to the assignee of the present application and incorporated herein by reference, addresses some of the shortcomings discussed above. However, the disclosed system does not provide specific auto-open and auto-close functionality in association with the vehicle's operational status. And the disclosed system does not provide for user-changeable sensitivity adjustments. Implementing a hands-free system that has universal settings for all home installations is extremely difficult. If one designs for optimum RF range, then the opening range of the barrier is improved, but in contrast, the closing range ends up being too high. If one does not design for optimum RF range then in worst case home installations, the opening RF range might not be sufficient. In other words, if the RF signal is too strong, the barrier opens at a distance relatively far away, but closes only out of sight of the user. Or, if the RF signal is too weak, then the user must wait for the barrier to open before entering the garage. Situations may also arise where a designated sensitivity level causes the operator to toggle between barrier opening and closing cycles before completion of a desired cycle.
U.S. patent application Ser. No. 10/962,224, assigned to the assignee of the present application and incorporated herein by reference, also addresses some of the shortcomings identified in the prior art. The '224 application discloses a specific embodiment wherein the mobile transponder is directly connected to the ignition system and power source of the carrying device. However, such an embodiment requires a specialized installation and does not permit easy transfer of the transponder between carrying devices. And the known hands-free devices all require periodic transmission of a radio frequency signal from the garage door operator. It is believed that this may lead to increased electrical “noise” pollution which adversely affects nearby electrical communication devices.
Therefore, there is a need in the art for a system that automatically moves access barriers depending upon the proximity of a device carrying a remote mobile transmitter, wherein the transmitter automatically emits somewhat periodic signals that are received by the operator which then moves the barrier and ignores subsequent transmitter signals for a predetermined period of time. And there is a need for the remote mobile transmitter to also consider the operational status of the carrying device by use of a sensor that may or may not be directly connected to the carrying device's electrical system. And there is a need for a user-changeable sensitivity adjustment for the mobile transmitter.